The constructor of each C++ CASTOR daemon now takes a reference to Log object

as a parameter.  The functions that create the CASTOR daemon objects all
create a castor::log::LogImplementation object and pass it to the constructor
of their corresponding CASTOR daemon object.  When unit testting, one now has
the posibility to develop a dummy Log object that implements the interface
with dummy or mock routines so that the unit tests can run without having to
write to syslog or rsyslog which is a bit heavy for unit tests.  The
castor::log::LogImplementation basically contains the logging code centered
around syslog that was developed by Sebastien and Dennis.

Please note that I now have to add one or more log functions to the base
class of the CASTOR daemon objects, namely castor::server::BaseServer.